Plenty of trails near north conway nh, just about 1.5 for you to get to the white mountains from Portland. Dozens of trails off the kankamangus, or at great glen trails, Jackson ski touring snowshoe trails, bear notch if you don't mind paying $25 or so. But some trail heads in white mt national forest are free, or pretty cheap to park at ($5) off the kankamangus.